js exam regex

function solve(input) {
    // let regex = /(?<username>U\\$[A-Z][a-z][a-z]+U\\$)(?<password>P@\\$[a-z]{5,}[1-9]+P@\\$)/gm
    // let regex1 = /U\$[A-Z][a-z][a-z]+U\$P@\$[a-z]{5,}[1-9]+P@\$/gm
    // let regex2 = /U\$(?<username>[A-Z][a-z][a-z]+)U\$P@\$(?<password>[a-z]{5,}[1-9]+)P@\$/g;
    //
    // let number = Number(arr[0]);
    // let count = 0;
    //
    // for (let i = 1; i <= number; i++) {
    //     let input =  arr[i];
    //     let match = regex2.exec(input);
    //     if(match){
    //         console.log('Registration was successful')
    //         console.log(`Username: ${match.groups.username}, Password: ${match.groups.password}`)
    //         count++
    //     }else{
    //         console.log('Invalid username or password')
    //     }
    // }

    input.shift();
    let count = 0;
    for (const line of input) {
        let regex = /U\$(?<username>[A-Z][a-z][a-z]+)U\$P@\$(?<password>[a-z]{5,}[1-9]+)P@\$/g;
        let match = regex.exec(line);
        if(match){
            console.log(`Registration was successful`);
            console.log(`Username: ${match.groups.username}, Password: ${match.groups.password}`);
            count++;
        }else{
            console.log(`Invalid username or password`);
        }
    }

    console.log(`Successful registrations: ${count}`)
}